a. Field of the Invention
The invention pertains to the catalytic production of styrene from toluene and formaldehyde.
b. Description of the Prior Art
Production of styrene from toluene and formaldehyde is important because styrene is a large volume commodity chemical, and toluene and formaldehyde are low cost sources of reactants.
Japanese Patent No. 52-133932(1977) and K. Tanabe et al React Kin Catal Lett. Vol. 7 347 (1977) describe the formation of styrene by reaction of toluene and methanol over alkali and alkaline earth metal oxides and hydroxides. But the process is not commercially useful because large amounts of ethylbenzene are produced as a co-product, which is expensive to separate from the styrene. Other catalytic processes use the alkali and alkaline earth metal substituted crystalline aluminosilicates, (see) Y. N. Sidorenko et al, Dokl. Akad. Nauk, USSR 173 132 (1967); and T. Yashima et al, J. Catal 26 303 (1972). Ethylbenzene, however, is also produced in these catalytic processes. U.S. Pat. No. 4,115,424 and U.S. Pat. No. 4,140,726 describe a catalytic process using toluene and formaldehyde with molecular sieve catalysts of the X or Y zeolite structure containing cesium, rubidium or potassium cations and boron or phosphorous, but this process also produces large amounts of ethylbenzene. These and other drawbacks of the prior art are overcome by the process described herein.